NTSB Factual Report

HISTORY OF FLIGHT

On November 18, 1995, about 1721 hours Pacific standard time, a Beech S35, N5795K, operated by Tri Air, crashed into a sand dune approximately 1.5 miles west of the Oxnard Airport, Oxnard, California. Instrument meteorological conditions prevailed at the time, and the pilot had received an instrument clearance to the airport. The airplane was substantially damaged, and the instrument rated private pilot was fatally injured. The flight originated from a private landing strip near Cuyuama, California, about 60 miles northwest of Oxnard at an unknown time. The pilot was executing a missed approach to Oxnard when the accident occurred.

The pilot contacted NAWS Pt. Mugu Tracon (Terminal Radar Approach Control) while over the area of Ojai (FIL 270 degrees radial at 18 DME) and requested an ILS approach into Oxnard. He said he had ATIS information "echo". Subsequently, he was vectored towards the ILS inbound course to runway 25. The pilot was cleared for the approach while inbound to Nelly intersection and was requested to contact the ATCT at the outer marker.

The pilot contacted the ATCT at the outer marker. The ATCT cleared him to land and requested he report a missed approach or on-the-ground as the local controller could no longer see the runway. The local controller advised approach control that this would be the last landing as they were down to 1/4 mile in fog.

Subsequently, the pilot was asked if he had just made a missed approach. He eventually said affirmative. The local controller requested he contact approach on 124.7, to which he acknowledged. About 20 seconds later over an open microphone, he was heard to say "can you hear me I'm... come on baby, come on, come on, come on." At the same time, a 434 Hz tone was recovered from the voice tape and it was determined to be a stall warning horn. According to FAA radar data the airplane never got above 200 feet msl during the missed approach. According to ATCT personnel, typically with this type of fog, the tops are about 1,000 to 1,500 feet msl.

The aircraft that had landed prior to the accident aircraft's approach landed safely. While taxiing, the tower personnel lost sight of the aircraft due to fog that was moving into the area and across the airport.

PILOT INFORMATION

The instrument rated private pilot's logbook was not recovered. According to information obtained from an insurance application, the pilot reported a total flight time of 2,000 hours with 1,500 retractable and 1,200 in the make and model of the accident airplane. It was further indicated that he had flown 30 hours in the last 12 months and 7 hours in the last 90 days. The pilot's last biannual flight check had been conducted on August 29, 1995, in the accident airplane.

AIRPLANE INFORMATION

An annual inspection was performed on the aircraft on October 17, 1995, and it was documented that the aircraft accumulated 5,054 total flight hours. The recording tachometer indicated 2,880 hours, and at the accident site the recording tachometer indicated 2,884.89 hours. The propeller total time was listed as 5,054 hours, with 249 hours since overhauled by Santa Monica Propeller Service on March 20, 1990, and the engine was documented as having 410 hours since a factory rebuild.

According to the engine log, on September 28, 1993, the propeller was dynamically balanced. A stack of nine washers were found attached with a AN525 screw and nut to a location on the spinner back plate. The total weight of the addition was 1.4 ounces.

WRECKAGE AND IMPACT INFORMATION

The wreckage site was located in an area of sand dunes about 200 yards from the beach of the Pacific Ocean. The initial impact point was determined by FAA inspectors to be about 35 feet long on a southwesterly magnetic heading. The Safety Board was not on-scene.

The FAA inspectors reported that there were no signs of leading edge damage to the propeller blades. They noted that there was red oil dripping from the propeller hub and signs of the oil being slung outward from No. 2 blade root. They also reported a red oil film over 50 to 60 percent of the windshield's center area, with additional signs on the VHF communications antenna.

METEOROLOGICAL INFORMATION

At 1647, the Oxnard weather was reported as: sky partially obscured, measured ceiling 500 feet overcast; visibility 1.5 miles in fog; temperature 60 degrees Fahrenheit, dew point 57 degrees Fahrenheit; wind 270 degrees at 10 miles per hour; altimeter 30.11 inHg; remarks: fog obscuring 7/10 of the sky.

At the time the pilot was cleared to land the local controller advised the pilot that he could no longer see the runway. At the same time, the controller advised approach that this would be the last landing as the visibility was down to 1/4 mile in fog. As the local controller advised approach control of the missed approach he also stated that they were weather obscured.

MEDICAL AND PATHOLOGICAL INFORMATION

The pilot was taken to the hospital with severe head injuries and subsequently succumbed to the injuries. The Ventura County Medical Examiner performed an autopsy on the pilot. During the autopsy samples were obtained for analysis by the FAA Civil Aeromedical Institute located in Oklahoma City, Oklahoma. The analysis was negative for Cyanide and Ethanol. The drug screen was negative except for Lidocaine, which was found in the pilot's blood at a level of 0.200 ug/ml, ug/g.

TESTING AND RESEARCH

ENGINE: The engine was removed and sent to the Continental Motors Factory at Mobile, Alabama, where on February 7, 1996, it was mounted in a test cell and ran to continental specifications under the supervision of the Safety Board.

PROPELLER: On January 30,1996, the propeller was taken to an FAA approved propeller repair station for disassembly and inspection by the manufacturer's representative and the Safety Board. Dye penetrant and eddy-current type inspection's were performed on the components. (See attached report.)

On May 8, 1996, the propeller governor was taken to an FAA approved propeller repair station for examination and functional testing. The governor was installed in a test fixture on a Greer Governmatic governor testing machine and tested to the manufacturer's specifications. The specifications for this installation require the governor to limit the propeller speed to 2,700 rpm + or - 10 rpm. The governor was tested to 2,680 rpm which was considered by the technician to be acceptable. The machine was due again for recalibration on December 15, 1996.

AUDIO TAPE: A certified audio cassette re-recording of the Oxnard local control (tower) was sent to the audio laboratory of the Safety Board. The good quality recording was examined to document any engine or propeller sounds that could be heard during radio transmissions from the accident aircraft.

The radio transmissions were examined on an audio spectrum analyzer to identify any background sound signatures that could be associated with either the engine or the propeller.

The three radio transmissions that were made while the aircraft was initially on the missed approach contained sounds that could be associated with the engine or the propeller. These sounds were measured at a frequency of 282-284 Hz and determined to be from the propeller rpm.

The accident airplane is equipped with a two blade propeller. According to the FAA certifications specifications, during a missed approach at full power propeller control forward the engine would normally reach 2,700 maximum rpm.

According to the results of the laboratory examination of the frequencies, during the missed approach over a period of 52 seconds the propeller rpm oscillated between a high of 2,844 rpm and a low of 2,220 rpm.

A background tone of 434 Hz was also recovered from the examination. According to Beech Aircraft, the S35 aircraft is equipped with a stall warning horn that has a frequency range of 420-450 Hz.

ENGINE MOUNTS: Two separated engine mount legs were sent to the Safety Boards Materials Laboratory for metallurgical analysis of the fracture surfaces. According to the report, both fractures were the result of impact. There were no signs of progressive cracking, and one leg had been repair welded.

SEATBELT: The pilot's seatbelt was found still fastened; however, the belt stitching on the left outboard belt half was found completely unstitched from it's hardware. On December 21, 1995, the seatbelts from the accident airplane were taken to a belt manufacturer for testing. The right front seatbelt halves were static pull tested to yield 1,520 pounds. A set of halves from a rear seat were also tested and they yielded at 1,900 pounds. The pull test fixture was last calibrated on November 10, 1995.

ADDITIONAL INFORMATION

The wreckage was released to the insurance company representative on May 8, 1996.

NTSB Probable Cause

failure of the pilot to maintain adequate airspeed during a missed approach, after encountering an undetermined propeller malfunction, which resulted in a stall and collision with the terrain. Factors relating to the accident were: darkness, fog, and the propeller malfunction.